1. Field of the Invention
This invention relates to peptides for inhibiting growth of microbial, and more particularly to antimicrobial peptides against pathogenic bacteria, including Gram-positive bacteria such as Streptococcus pneumoniae, and Gram-negative bacteria such as Escherichia coli. 
2. Description of Related Arts
Streptococcus pneumoniae is a gram-positive, alpha-hemolytic capsulated anaerobe bacteria that commonly present as normal flora in the human upper respiratory tract. It is a major cause of severe infections such as meningitis, sepsis, pneumonia, acute otitis media, endocarditis, and others. Those at the extreme age groups are frequently infected by pneumococci.
The world health organisation (WHO) estimated that in year 2005, as high as 0.7-1 million deaths due to pneumococcal diseases were children of age 5 and below. In the course of treatment of pneumococcal infection, β-lactam antibiotics especially penicillin and cephalosporin remain as the main antibiotics prescribed. However, these antibiotics as well as other conventional antibiotics have observed reduced efficacy following widespread clinical, veterinary, and agricultural uses. The antibiotic selection pressure favors the resistant strains hence leading to continued expansion of antibiotic resistant strains. Moreover, S. pneumoniae is naturally transformable whereby exogenous resistance genes can be acquired via horizontal transformation from the environment surrounding the cells. The recombined strains thus possess enhanced survival advantage and are able to escape from the killing activity by the antibiotics leading to the increasing reports of antibiotic resistant pneumococci worldwide. Therefore, there is a need to have an alternative antimicrobial agent to effectively overcome said problem.
U.S. Pat. No. 7,960,339 B2 disclosed polypeptide and lipopolypeptide having microbial and endotoxin-neutralising activities. These molecules show a broad spectrum of activity against various pathogens (including bacteria, viruses, fungi etc). However, the cited patent disclosed set of amino acid sequences which are different and targeting different microbial.
US 2007/0021601 A1 disclosed isolated polypeptide and nucleic acid sequences derived from Streptococcus pneumoniae that is useful in diagnosis and therapy of pathological conditions. Although the cited patent disclosed polypeptide sequences that provides protective immunity against infection by Streptococcus pneumoniae, the limitation of the use is a disadvantage, thus there arise a need to have alternate polypeptide sequences that are not just limited for Streptococcus pneumoniae infection but to other bacterial pathogen as well.
Accordingly, it can be seen in the prior arts that there exists a need to provide peptides for prohibiting Streptococcus pneumoniae infection and other bacterial pathogens infection.